MERLIN/ALIS-2/RS-ARQ /RS ARQ
This is the 240 bd 8 tone burst ARQ mode used in the
Rohde & Schwarz MERLIN modem. When the system is found
in the 7 tone mode it is in ISS mode, the IRS mode
uses an 8 tone signal. Both will be measured as 240 bd
(720 bits/sec) with tones shifted by 240Hz. Character
set can be ITA2 or ASCII with 8 bit ASCII being the
Turkish, German and Italian Diplo stations are the
most commonly found users.
The Italian Diplo stations
seem to favor the 5 bit (ITA2) mode. Turkish Diplo
stations have been found using the 8 bit mode for all
Its been discovered that all 8 tone channels have ALIS
(228.7bd) 2kHz below. So if you hear an ALIS procedure
in progress on a frequency it's worth waiting to see if
8 tone traffic appears 2kHz higher soon after.